Holo-krome 64066 Button Socket Cap Screw 3/8-16 5/8in

Product Description

The HOLO-KROME 64066 is a button head socket cap screw designed for applications requiring a low-profile, high-strength fastener with a clean seating surface. Manufactured from alloy steel with a black oxide finish, it features a 3/8-16 UNC thread and a 7/32-inch hex socket drive. The button head profile reduces snag points in tight clearance areas while the alloy steel construction delivers hardness rated at 38 HRC. The black oxide coating provides mild corrosion resistance and a consistent dark appearance. This fastener is fully threaded and carries a Thread Fit Class 3A designation, conforming to ANSI/ASME B18.3 and ASTM F835 standards. It is installed by maintenance technicians, millwrights, and mechanical contractors across a wide range of industrial and commercial assembly work.

This screw is suited for residential and commercial mechanical assemblies, machine guards, equipment enclosures, and fixture mounting where a low-profile head is preferred over a standard socket head cap screw. The 3/8-16 UNC thread is one of the most common coarse-thread sizes in North American trade work, making this fastener broadly applicable across HVAC equipment frames, electrical enclosures, and general mechanical sub-assemblies. Right-hand thread direction follows standard convention. The black oxide finish is appropriate for indoor and low-moisture environments.

Key Features

• Button head profile with 0.656-inch head diameter for low-profile, snag-resistant seating
• Alloy steel construction hardened to 38 HRC for high clamping load capacity
• Black oxide finish for mild corrosion resistance and uniform appearance
• 3/8-16 UNC fully threaded, Thread Fit Class 3A for precision engagement
• 7/32-inch hex socket drive compatible with standard hex keys and bit drivers
• Conforms to ANSI/ASME B18.3 and ASTM F835 fastener standards

Compatibility

Designed as a standard 3/8-16 UNC button socket cap screw per ANSI/ASME B18.3, suitable as a direct replacement or new-installation fastener wherever a 3/8-16 button head socket cap screw is specified.

Installation Notes

Install and remove using a 7/32-inch hex key or socket bit driver. Power down and de-energize any equipment before accessing fastened assemblies. Follow applicable mechanical and safety codes for the specific equipment type being serviced. Do not exceed the structural capacity of the mating material — alloy steel fasteners can generate clamping loads that may strip threads in softer base materials such as aluminum or plastic.